- Feather pecking in laying hens housed in free-range or furnished-cage systems on French farms. [Journal Article]
- BPBr Poult Sci 2019 Jul 03
- Beak trimming is currently used in France to avoid the negative consequences of severe feather pecking (SFP). However, this practice is controversial in terms of animal welfare, and forbidden in some…
Beak trimming is currently used in France to avoid the negative consequences of severe feather pecking (SFP). However, this practice is controversial in terms of animal welfare, and forbidden in some European countries. This study aimed to assess the prevalence of SFP in French laying hen farms, to describe how farmers manage this behavioural disorder and to better understand the risk factors involved. A study was carried out from April 2015 to June 2016. Visits were paid to 79 flocks kept in furnished cages (FC) and 80 flocks in a free-range (FR) system. All the hens had trimmed beaks and were genotypically brown. The information collected included feather cover, skin damage, beak condition, farm and poultry house characteristics, livestock performance and management. The prevalence of SFP in FC flocks was estimated at 32.9% (IC=95%, [22.5; 43.3]) and the prevalence of cannibalism as 2.5% (IC=95%, [0.7; 8.8]) at 70 weeks of age. The prevalence of SFP in FR flocks was estimated to bet 23.8% (IC=95%, [14.5; 31.1]) and the prevalence of cannibalism was 8.8% (IC=95%, [4.3; 17.0]) at 61 weeks of age. In FC flocks, SFP was associated with the combination of genotype, type and length of perches, cage area per hen, type of lighting, number of hens per cage and farm location. In FR flocks, feather cover was associated with use of the outdoor run, lighting programme, genotype, farm location and date of house construction.
- Cyclic prey evolution with cannibalistic predators. [Journal Article]
- JTJ Theor Biol 2019 Jun 29; 479:1-13
- We investigate the evolution of timidity in a prey species whose predator has cannibalistic tendencies. The ecological model is derived from individual-level processes, in which the prey seeks refuge…
We investigate the evolution of timidity in a prey species whose predator has cannibalistic tendencies. The ecological model is derived from individual-level processes, in which the prey seeks refuge after detecting a predator, and the predator cannibalises on the conspecific juveniles. Bifurcation analysis of the model reveals ecological bistability between equilibrium and periodic attractors. Using the framework of adaptive dynamics, we classify ten qualitatively different evolutionary scenarios induced by the ecological bistability. These scenarios include ecological attractor switching through catastrophic bifurcations, which can reverse the direction of evolution. We show that such reversals often result in evolutionary cycling of the level of timidity. In the absence of cannibalism, the model never exhibits ecological bistability nor evolutionary cycling. We conclude that cannibalistic predator behaviour can completely change both the ecological dynamics and the evolution of prey.
- What is your diagnosis? Lymphocytes engulfing erythrocytes in a cat. [Journal Article]
- VCVet Clin Pathol 2019 Jun 28
- IGF1R Is a Potential New Therapeutic Target for HGNET-BCOR Brain Tumor Patients. [Journal Article]
- IJInt J Mol Sci 2019 Jun 21; 20(12)
- CONCLUSIONS: IGF1R is as an attractive target for the development of new therapy protocols for HGNET-BCOR patients, which may include ceritinib and vinblastine.
- What is your diagnosis? Thoracic mass in a dog. [Journal Article]
- VCVet Clin Pathol 2019 Jun 23
- Does optimal foraging theory explain the behavior of the oldest human cannibals? [Journal Article]
- JHJ Hum Evol 2019; 131:228-239
- Cannibalism is an old and widespread human practice; however, the causes and meaning of consuming other humans are still hotly debated. Several explanations are possible for cannibalistic behavior, r…
Cannibalism is an old and widespread human practice; however, the causes and meaning of consuming other humans are still hotly debated. Several explanations are possible for cannibalistic behavior, ranging from social and cultural motivations to purely nutritional causes. In this study, we analyze the oldest known case of cannibalism to date in the framework of the Optimal Foraging Theory (OFT). The fossil assemblage from the TD6.2 unit of the Gran Dolina site (Sierra de Atapuerca, Spain), dated to c. 0.9 Ma, includes the remains of several hominins (Homo antecessor) with unquestionable signs of cannibalism and a large collection of fossils of other mammals, also with evidence of human consumption. The Optimal Foraging Theory predicts that foragers confronted with a number of options aim to maximize their return rate, obtaining the maximum benefit with the minimum cost. We estimated the nutrient caloric return and the cost of acquisition of humans and other large mammals in TD6.2, and evaluated the rank of hominins among all the food resources harvested by H. antecessor using a Prey Choice Model (PreyCM). We also show that the abundance of the different prey types represented in the TD6.2 assemblage is proportional to the abundance of those resources in the environment, a prediction of the OFT. Although TD6.2 assemblage fits the predictions of the PreyCM, humans are overrepresented with respect to their estimated abundance in the environment. This overrepresentation of hominins was likely due to a higher encounter rate, as may be expected if the cannibalized individuals belonged to the same group as the foragers, although other explanations are possible. The results presented here show that hominins were a high-ranked prey type and, thus, their inclusion in the diet of H. antecessor is predicted by the OFT.
- Cell cannibalism in oral cancer: A sign of aggressiveness, de-evolution, and retroversion of multicellularity. [Journal Article]
- JCJ Cancer Res Ther 2019 Jul-Sep; 15(3):631-637
- CONCLUSIONS: With increase in dedifferentiation, tumor cells start behaving like unicellular organisms with cell eating cell characteristics.
- Efferocytosis perpetuates substance accumulation inside macrophage populations. [Journal Article]
- PBProc Biol Sci 2019 Jun 12; 286(1904):20190730
- In both cells and animals, cannibalism can transfer harmful substances from the consumed to the consumer. Macrophages are immune cells that consume their own dead via a process called cannibalistic e…
In both cells and animals, cannibalism can transfer harmful substances from the consumed to the consumer. Macrophages are immune cells that consume their own dead via a process called cannibalistic efferocytosis. Macrophages that contain harmful substances are found at sites of chronic inflammation, yet the role of cannibalism in this context remains unexplored. Here we take mathematical and experimental approaches to study the relationship between cannibalistic efferocytosis and substance accumulation in macrophages. Through mathematical modelling, we deduce that substances which transfer between individuals through cannibalism will concentrate inside the population via a coalescence process. This prediction was confirmed for macrophage populations inside a closed system. We used image analysis of whole slide photomicrographs to measure both latex microbead and neutral lipid accumulation inside murine bone marrow-derived macrophages (104-[Formula: see text]) following their stimulation into an inflammatory state ex vivo. While the total number of phagocytosed beads remained constant, cell death reduced cell numbers and efferocytosis concentrated the beads among the surviving macrophages. As lipids are also conserved during efferocytosis, these cells accumulated lipid derived from the membranes of dead and consumed macrophages (becoming macrophage foam cells). Consequently, enhanced macrophage cell death increased the rate and extent of foam cell formation. Our results demonstrate that cannibalistic efferocytosis perpetuates exogenous (e.g. beads) and endogenous (e.g. lipids) substance accumulation inside macrophage populations. As such, cannibalism has similar detrimental consequences in both cells and animals.
- The Psychopathological Profile of Cannibalism: A Review of Five Cases. [Journal Article]
- JFJ Forensic Sci 2019 Jun 03
- In today's society, human cannibalism is extremely rare and represents an unthinkable act of violence. Scientific literature on the topic is sparse due to significant methodological problems, such as…
In today's society, human cannibalism is extremely rare and represents an unthinkable act of violence. Scientific literature on the topic is sparse due to significant methodological problems, such as collecting enough data and generating unbiased analyses. The purpose of this article is to illustrate some psychodynamic aspects of cannibalism. After a review of the literature, we will present and compare five cannibalistic patients hospitalized in the Henri Colin secure unit (Villejuif, France). The patients described fall into two subgroups, suffering either from severe schizophrenia or from a mixed personality disorder with sadistic and psychopathic features associated with paraphilia. For the schizophrenia group, cannibalism is a self-defense reaction to a perceived threat of destruction: survival depends on the annihilation or assimilation of the other. For the mixed personality disorder group, ego and narcissism are the central issue with a desire to overcome deep-rooted frustrations by means of an extraordinary act.
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- Intra-community infanticide in wild, eastern chimpanzees: a 24-year review. [Journal Article]
- PPrimates 2019 May 27
- Infanticide is well documented in chimpanzees and various hypotheses have been proposed to explain this behavior. However, since infanticide by chimpanzees is relatively rare, it has thus far not bee…
Infanticide is well documented in chimpanzees and various hypotheses have been proposed to explain this behavior. However, since infanticide by chimpanzees is relatively rare, it has thus far not been possible to thoroughly test these hypotheses. Here we present an analysis of the largest dataset of infanticides from a single community of chimpanzees, a full record of all intra-community infanticides and failed attempts at infanticide over a 24-year period for the Sonso community of chimpanzees in the Budongo Forest, Uganda. We use these data to test four hypotheses for this behavior: the sexual selection hypothesis, male mating competition, resource competition, and meat acquisition. Our dataset consisted of 33 attacks on 30 victims, 11 of which were 'definite' infanticides, four of which 'almost certain', and nine were 'suspected', while nine were 'attempted' infanticides. The majority of attacks where the perpetrators were known (23) had only male attackers and victims were disproportionately young (two-thirds of victims with known ages were under 1 week old). Our data best support the sexual selection hypothesis for infanticide. Cannibalism was infrequent and partial, suggesting meat acquisition was a by-product of infanticide, and there was no evidence to suggest that infanticide was part of a male strategy to eliminate future competitors. Infanticide by females was rare, but we suggest sexual selection, operating through intra-sexual competition, may also be responsible for infanticide by females.